chgrp
From NetBSD Wiki
The chgrp(1) command changes the group ownership of a file.
Example:
$ ls -l force -rw-rw-r-- 1 luke jedi 0 Jan 1 10:10 force $ chgrp rebels force $ ls -l force -rw-rw-r-- 1 luke rebels 0 Jan 1 10:10 force
With the -R switch you can have chgrp(1) recurse down subdirectories.
